Problem: Khan.scratchpad.disable(); To move up to the maestro level in her piano school, Ashley needs to master at least $131$ songs. Ashley has already mastered $42$ songs. If Ashley can master $4$ songs per month, what is the minimum number of months it will take her to move to the maestro level?
To solve this, let's set up an expression to show how many songs Ashley will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Ashley Needs to have at least $131$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 131$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 131$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 4 + 42 \geq 131$ $ x \cdot 4 \geq 131 - 42 $ $ x \cdot 4 \geq 89 $ $x \geq \dfrac{89}{4} \approx 22.25$ Since we only care about whole months that Ashley has spent working, we round $22.25$ up to $23$ Ashley must work for at least 23 months.